Trailer/Hauling paranoia.

[JBailey]

I am confounded with unknowns. I know many of you out there have had lots of experience with trailers and hauling equipment. I haven't. The attached picture is of my latest project, a Sprout-Waldron grist mill connected to a John Deere LUC all mounted on a 10' single axle trailer. I have built a roof over the equipment as shown in the picture. I figure all in all, the mill, engine, and roof weigh in the neighborhood of 1,200 to 1,400 pounds. Trailer probably weighs another 1,000. So, I'm well within the 3,500 pounds that the trailer is rated. The tongue weight is 220 pounds. I'm concerned about the aerodynamics of the trailer. I will never have this trailer on the Interstate. It will probably never travel more than 45 to 50 mph. Will there be enough lift generated at that speed to cause the trailer to be unstable? I've been told that I should make the front end lower than the rear to reduce lift. But, the receiver hitch on my truck is about 16" off the ground while the tongue on the trailer at level is about 9" off the ground. So, even with a 4" drop receiver hitch, the front of the trailer is going to be 3" higher than the rear.

As you can tell from the picture, the roof is pretty stout. I used screws to attach the tin and used probably twice as many screws as I would have were the roof stationary. I'm not worried about the tin coming loose. What I'm concerned about is the lift created by the air flow over the trailer possibly causing it to be unstable and possibly leading to a catastrophe.

Call me paranoid. I am. Can somebody out there shed some light that will ease the paranoia? Have I just wasted a bunch of time and money? Or am I just being foolish?

[Chip Watford]

I don't think your being foolish at all.You're just using "common sense" which seems to be in short supply nowadays.Good job!The only thing that I think you should do is add some diagonal bracing at the top of the posts where they meet the roof.I've built many pole barns and sheds and diagonal bracing is where all your stability is.That is light gauge angle that the posts are bolted to and I wouldn't trust just that to hold the roof up in the wind and around curves.As far as pulling goes,I would try it at 20 mph then 30,then 40 etc. and see how it does.If you are worried about air getting under it ,you might consider a piece of ply wood to attach across the front but could be removed at the show.This would also help with side to side stability.Just my thoughts and opinions! Chip

[Michael E. McCracken]

You could go with bigger tires and rims. That would bring your tongue up to be level with hitch.

[Bryan Storey]

If you would like to keep the trailer more level while it is on your pickup they do have drop hitches that are more than 4". I have a one ton pickup and run into the same problem as you with smaller trailers being out of level. I went out and bought a 6" and later an 8" drop hitch that goes into the receiver. Its nice to have the trailer level when you take it to a show and dont want to un hook from your truck.

[MoRo]

The weight of the engine and mill will not allow the trailer to become unstable. The only worry you have is making sure that the roof and structure survive the trips.
~M~

[Joe Musser]

I would go with the better angle bracing on the posts so the roof doesn't twist under stress, but as far as wind causing lift, it doesn't look like a wing to me so I doubt it will fly well at all, but if you don't mind the extra drag caused by the flat plywood, that will brace the roof up as well as or better than angle braces and would make you feel better too perhpaps. And if it does fly patent it, blow outs on trailers would be a thing of the past. Seriously I think the only problem you might have after you get better bracing will be your gas milage the roof will cause a lot of drag.

[Jebaroni]

With the weight of the engine and the mill, plus the trailer weight, there is no way that thing is coming off the ground. If the trailer were empty, you may have a valid concern, but loaded as is, it will be seriously bottom heavy and I wouldn't worry about it. The diagonal bracing is still a good idea, though. You are wise to voice your concerns up front and verify things like this. As others have said, good job on the trailer. Now, you wouldn't happen to know where I could get a pulley and wrench for my Little Wonder mill, would ya? Take it easy and enjoy the shows!

Jeb

[Frank Douglas]

John, as you know I have seen that photo before. My wife's comment was "Is he gonna pull that thing down the road?" I agree that some diagonal bracing would be a wise addition. Good luck and that is a great job!

Frank

[TBuchanan]

You have overlooked the important aspect of this problem, liability.
If that roof comes apart and hurts someone you will certainly wish it had a removable tarp instead of potentially lethal objects.

[Meco3hp]

Hello,
I'm not a aerodynamic engineer, but the only way you'd get lift from that roof is sideways at 120+mph.(easy to fix with some handi NASCAR roof flaps ) With the hitch configuration you have, I'd be more worried about it turning into a para-brake! I'd look for a lower receiver hitch or go with the big tires/rims ideas. I'd also add some bracing to the uprights. Other wise, good job, and a nice setup.

Thanks
Richard

[KidDynamo]

Perhaps your anxiety arises from the unpredictable. Testing will help but it is hard to simulate all possible conditions, isn't it?

Creating lift is one thing that may or may not occur but piling up air underneath the roof could push with quite a lot of force too. There are enough square inches to accumulate significant net force if conditions are just right (wrong, I guess I mean).

If the entire enclosure could be tarped, top included, and the tarp secured from flapping itself to pieces, you would significantly reduce the chance of having parts flying off and going through someone's windshield and you'd be adding rain protection and some level of theft/vandalism protection as well.

Several courses of cheap 1 by 3 boards could be screwed to the uprights to give a tarp a framework to "land" on This stuff could be removed upon arrival to regain the openness of your design. If you dislike wood for this purpose, a rope grid might suffice.

A "pointy end" like a boat's bow could spill the air pressure around the tarp's front and prevent the tarp from pooching inward but would require some additional framing.

Just a few ideas to throw around or throw away as you see fit. Nice display !!

[Andrew Mackey]

Go first with the deeper drop type hitch, to better level the trailer. Next, buy a good cloth tarp, one made of tent material. These are sold at military surplus stores, and are sometimes called dining hall tarps. Cover the entire roof, and as much of the sides and front as possible. This will protect the roof and the interior from wind blast and road grime and debris. The dining tarps have eyelets sewn in, and you can tie it down securely. You can also purchase parachute cord there as well. this is light weight, and extremely strong cordage, and is inexpensive to boot! The tarp 'breathes', so you don't have to worry about moisture being trapped under it, like you would with a plastic tarp, and the cloth type has a much greater tear resistance than the plastic. Tarping the entire load to the front of the trailer will also make it more aero-dynamic!
Andrew

[Mark B]

Just one more idea. How about a plywood curve (front to back) underneath the top. Perhaps make an airfoil under the top to create "lift" but towards the ground.

[David Greenwalt]

Hi, what you could do is find some lightweight 1 inch square tubing and make a frame. Put plywood, or tin, on it and go ahead and enclose the trailer. But hinge the top of the panels and pin the bottom, then when you get to the show just lift them up and have extra roofing to sit under and keep out the rain and sun. This would give you extra support, shade, and a permanent shed to keep your equipment in at home. David.

[RHudson]

I agree with others on adding diag. bracing. maybe temp. cables that could be taken off at show. maybe screwing plywood to your 4 x 4.s. if you have any porblem, i would say it would be from the corrigated roofing vibrating and finally splitting from fatigue.
I recently had a 16 ft trailer overloaded big time. i traveled the interstate late at night until around 5:00 and there was so little traffic i had little to worry about....if you think you will be traveling slower than 15 mph below traffic flow, i would invest in two yellow flashing lights and mount them high up on your rear 4x4's. The yellows are suppost to notify those behind you that there is something in front of them that needs extra percaution. when and if you have to merge onto a road and you know you are going to be going extra slow until you get up to your normal traveling speed, use your emergency flashers until up to speed.

I always check load within the first 30 minutes of travel, then about every 2 hours after that. in your case, watch for movement of your bolts with in the wooden members. be aware that the air flow of vehicles around you will affect your line of traffic. (when an 18 wheeler passes you, your rig will tend to be pushed away from it, then, pulled toward it)

i always worry about this stuff. and prepare for it. if you would like to email me for advise, please feel free to do so.

By the way....very nice rig....it looks great.

how much curve is in the top and how did you do it? I want to do the same with a couple of oilfield engines i have. i thought i would have to run the roofing front to back, but after looking at your roof. maybe i Could form it side to side.

[Chuck Parcher (Ks.)]

This is hard for me, i know how much work and expense you put into this project and to criticize it is awkward at best. I think what i would have done, is buy some 2" PVC pipe cut it to length and make a gabled slip together frame that i could put up in no time at a show and cover the roof with a tarp a portable shade cover to be erected at the show. For transport i would go with the drop hitch, or/and larger rims and tires until level. I would just tarp the equip in foul weather and keep the weight and center of gravity down plus the air resestance. I know when you have an idea, and then you build it you want it to work, and everyone appretiate your effort. Well sitting where it is it looks good, but me personally i would'nt want to tow it myself, but that's just my opinion. I do think the liability issue is there, but you would have to decide that for yourself. i would make a slip together frame and put it up at the shows. I hate suggesting things like this or criticizing anyone efforts but that thing looks scary to me. I'm sorry, but you asked for comment and this is mine.

Good luck with your project
Chuck

[Lou Quirch]

If it will make you feel better, you can put some cross bracing from the top front to the middle bottom that you can remove at shows, make sure the sheet metal is well fastened and go for it. If you surround it with anything it will create drag, put stress on the 4x4"s and use more gas. That roof will in no way act as an air foil (remember Wilbur and Orville). As soon as you enclose it, the passing trucks will suck it in and out.
I have many thousands of miles towing trailers, and the ones I find the hardest to tow are the enclosed boxes (we have a 26' ).

Lou

[JBailey]

Thanks to everybody for the great advice. I'm feeling more confident now. Please remember what I said in my original post, I never plan on towing this rig long distances on the Interstate. Most trips will only be for a few miles and probably never at more than 45 MPH.

What about putting about a two foot knee wall across the front of the trailer at the roof line? I know this would cause some drag but it would decrease the flow of air under the tin roof and possibly the chance of tin getting blown off. Someone told me this would increase lift and decrease stability because it would be restricting the flow of air under the roof and thus the equalizing pressure.

What an adventure....

[Ralph Leonard]

Well, I agree with Chuck, this is a difficult responce even when you show doubts and seem to be asking for help.

The first thing that jumped out at me was top heavy. Single axle trailers bouce badly at any speed. Those long post will have a lot of leverage to damage that lite weight frame.

I see stress from road shock more of a problem than air flow/lift. Open sides provide little or no weather protection. Salvage the materials for a storage shelter and use a removable cover at shows. I'm sorry its not what you wanted to hear, but that's my honest opinion

[Havvey]

nice job nice display but for travel i agree with chuck parcher a canopy that can be quickly dismounted would be the best way. the others are correct on tires and hitch set up. i have seen a trailer that is enclosed and the sides come off and you have a roof kind of like a food consession trailer. liability is always an issue today.